This invention relates in general to flexible couplings for use in the steering systems of vehicles, and in particular to an improved construction for a pinch bolt yoke for use in a vehicle steering system.
A vehicle steering system includes a steering wheel connected to a steering column. The steering column, in turn, is connected to an intermediate steering shaft. The intermediate steering shaft is connected at its other end to a steering gear. The steering gear, in ram, is connected to the front wheels of the vehicle. The vehicle steering system transfers the rotational motion of the steering wheel to the front wheels of the vehicle to cause the vehicle to turn.
The steering column, intermediate steering shaft, and steering gear are not axially aligned with one another. Consequently, flexible couplings are provided between the steering column and the intermediate steering shaft, and between the intermediate steering shaft and the steering gear. The flexible couplings allow proper connection of the steering column, intermediate steering shaft, and steering gear when these structures are rotated.
Pinch bolt yokes have been used as flexible couplings in a vehicle steering system. For example, pinch bolt yokes have been used as flexible couplings between a steering column and an intermediate steering shaft. The steering column includes a shaft portion. A notch for a transverse bolt is formed on the shaft portion. The pinch bolt yoke includes a bore and transverse apertures. When it is desired to connect the steering column to the pinch bolt yoke, the shaft portion of the steering column is inserted into the bore of the pinch bolt yoke. The transverse apertures of the pinch bolt yoke are aligned with the notch formed on the shaft portion. A transverse bolt is inserted through the transverse apertures and notch to complete the connection.
By way of background, steering columns are manufactured in many different sizes and configurations for use in a variety of different vehicles. The shaft portion of the steering column comes in different sizes. It can be cylindrical, rectangular or squared, and its surface can be splined or keyed. The notch for the transverse bolt can be positioned at different locations on the shaft portion. The transverse bolt can also be different sizes.
A conventional pinch bolt yoke is a forged one-piece construction. Unfortunately, such a one-piece construction is suitable for use with only one kind of steering column. Whenever the shaft portion of the steering column is changed, a pinch bolt yoke with a different bore is selected so that the bore is suitable for receiving the shaft portion. Likewise, whenever the positioning or size of the transverse bolt is changed, a pinch bolt yoke with different transverse apertures is selected so that the transverse apertures are suitable for receiving the transverse bolt. Thus conventional pinch bolt yokes are manufactured in many different designs to be suitable for use with the many different steering columns. As a result, conventional pinch bolt yokes have been relatively costly to manufacture. Moreover, the need for different pinch bolt yoke designs in different vehicles has been troublesome and expensive to vehicle manufacturers and mechanics.
Therefore, it would be desirable to provide an improved construction for a pinch bolt yoke which requires fewer designs and is relatively inexpensive to manufacture.